The addition of progesterone to estrogen has been shown in some studies to decrease its vasodilatory effects and also to diminish beneficial changes in lipids. Although concurrent use of progesterone is commonly recommended for women on estrogen replacement because of concerns in regard to enhancing risk of endometrial cancer, use of unopposed estrogen for periods of less than one year. It is desirable to clarify whether addition of estrogen replacement to lower fat diet may produce greater than individual treatment of itself.